Chest wall and neuromuscular diseases are common disorders which account for a major cause of hypercapnic chronic respiratory failure. Noninvasive home mechanical ventilation (NIHMV) is considered the treatment of choice in these patients when respiratory failure is well established. Adaptation process to NIHMV can be performed either in the hospital setting or ambulatory. Because few studies have evaluated the superiority of one setting over another for adapting to NIHMV, the choice has been based on the preferences or possibilities of each team of health professionals. Other essential factors of major interest, but poorly studied, are the long-term evolution of patients with NIHMV and variables associated with mortality. This thesis main objectives were to compare the effectiveness and costs of adaptation to NIHMV performed in the ambulatory or hospital setting in patients with chronic respiratory failure secondary to neuromuscular diseases or chest wall disorders. Another objective was to analyze mortality and prognostic factors of a cohort of patients with chest wall disease following NIHMV. In this thesis, two studies were conducted, a multicenter randomized clinical trial that evaluated the effectiveness using partial pressure of carbon dioxide in arterial blood (PaCO2) baseline and at six months following initiation of NIHMV in each adaptation group (outpatient and inpatient), as well as economic costs for each group. The second study was a prospective observational study that analyzed mortality, and its possible associated variables, in a cohort of patients with NIHMV. Both studies main results were that adaptation to NIHMV in the ambulatory setting is not inferior to hospital adaptation in terms of therapeutic equivalence in stable patients with chronic respiratory failure secondary to neuromuscular or chest wall diseases, and outpatient adaptation may represent a cost saving for the healthcare system. In addition, PaCO2 levels higher or equal to 50 mmHg at one month after starting NIHMV and the presence of comorbid conditions are risk factors for mortality in patients with chronic respiratory failure secondary to chest wall disease.
As a conclusion, in routine clinical practice, outpatient adaptation to NIHMV remains an option to be considered since it may represent a cost saving for the healthcare system, and once the patient is adapted to NIHMV, PaCO2 at one moth provides relevant information that might help to set for therapeutic decisions.